Project Summary The overall goal of this Center is to understand the neural network associated with obsessive-compulsive disorder (OCD). The data collected by Center investigators comes from a wide range of sources including studies of rodents, primates and humans. One of the major aims of the Center will be to broaden our understanding of the functional neurocircuitry of the anterior cingulate, orbital, and ventrolateral prefrontal cortices as they relate to abnormalities in OCD. The overall mission of the anatomy core is to provide the bridge between projects to identify structures that are likely to be affected by the disorder and modulated by neural stimulation across species. To achieve this goal, the anatomy core will work closely with each of the individual projects and Core C, to develop cross-species models of structures and pathways. The first aim of Core B is to provide support for the rat histology studies (P5) by assisting in tissue-processing in developing a rodent model of the cortical and striatal nodes that connect the amygdala and infralimbic cortex to the dorsal anterior cingulate and orbitofrontal cortex. The second aim of core B is to provide support for dMRI studies that require assistance in acquisition, processing, and data analysis (P1, 4). For this aim, Core B will be responsible for collecting diffusion dMRI data on non-human primate brains that will have been injected with tracers for P1. It will also be responsible for collecting dMRI data on cingulotomy patients for P1 & 3. Finally, it will provide support to P1-2, and 4 for analysis and data sharing.